OpenBSD 5.8 and 5.9 allows certain local users with kern.usermount privileges to cause a denial of service (kernel panic) by mounting a tmpfs with a VNOVAL in the (1) username, (2) groupname, or (3) device name of the root node.

thrsleep in kern/kern_synch.c in OpenBSD 5.8 and 5.9 allows local users to cause a denial of service (kernel panic) via a crafted value in the tsp parameter of the __thrsleep system call.

OpenBSD 5.8 and 5.9 allows local users to cause a denial of service (assertion failure and kernel panic) via a large ident value in a kevent system call.

Integer overflow in the amap_alloc1 function in OpenBSD 5.8 and 5.9 allows local users to execute arbitrary code with kernel privileges via a large size value.

Integer truncation error in the amap_alloc function in OpenBSD 5.8 and 5.9 allows local users to execute arbitrary code with kernel privileges via a large size value.

The mmap extension __MAP_NOFAULT in OpenBSD 5.8 and 5.9 allows attackers to cause a denial of service (kernel panic and crash) via a large size value.

Use-after-free vulnerability in OpenSMTPD before 5.7.2 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via vectors involving req_ca_vrfy_smtp and req_ca_vrfy_mta.

A flaw exists in OpenBSD's implementation of the stack guard page that allows attackers to bypass it resulting in arbitrary code execution using setuid binaries such as /usr/bin/at. This affects OpenBSD 6.1 and possibly earlier versions.

OpenBSD 5.8 and 5.9 allows certain local users to cause a denial of service (kernel panic) by unmounting a filesystem with an open vnode on the mnt_vnodelist.

Integer overflow in the uvm_map_isavail function in uvm/uvm_map.c in OpenBSD 5.9 allows local users to cause a denial of service (kernel panic) via a crafted mmap call, which triggers the new mapping to overlap with an existing mapping.

OpenBSD 5.8 and 5.9 allows local users to cause a denial of service (NULL pointer dereference and panic) via a sysctl call with a path starting with 10,9.

LibreSSL 2.5.1 to 2.5.3 lacks TLS certificate verification if SSL_get_verify_result is relied upon for a later check of a verification result, in a use case where a user-provided verification callback returns 1, as demonstrated by acceptance of invalid certificates by nginx.

httpd in OpenBSD allows remote attackers to cause a denial of service (memory consumption) via a series of requests for a large file using an HTTP Range header.

The OpenBSD qsort() function is recursive, and not randomized, an attacker can construct a pathological input array of N elements that causes qsort() to deterministically recurse N/4 times. This allows attackers to consume arbitrary amounts of stack memory and manipulate stack memory to assist in arbitrary code execution attacks. This affects OpenBSD 6.1 and possibly earlier versions.

The sys_thrsigdivert function in kern/kern_sig.c in the OpenBSD kernel 5.9 allows remote attackers to cause a denial of service (panic) via a negative "ts.tv_sec" value.

OpenSMTPD before 5.3.2 does not properly handle SSL sessions, which allows remote attackers to cause a denial of service (connection blocking) by keeping a connection open.

openssh: out-of-bounds read in packet handling code

The ssh_packet_read_poll2 function in packet.c in OpenSSH before 7.1p2 allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via crafted network traffic.

openssh: Incorrectly set TTYs to be world-writable

sshd in OpenSSH 6.8 and 6.9 uses world-writable permissions for TTY devices, which allows local users to cause a denial of service (terminal disruption) or possibly have unspecified other impact by writing to a device, as demonstrated by writing an escape sequence.

openssh: Denial of service via very long passwords

The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, which allows remote attackers to cause a denial of service (crypt CPU consumption) via a long string.

openssh: XSECURITY restrictions bypass under certain conditions in ssh(1)

The x11_open_helper function in channels.c in ssh in OpenSSH before 6.9, when ForwardX11Trusted mode is not used, lacks a check of the refusal deadline for X connections, which makes it easier for remote attackers to bypass intended access restrictions via a connection outside of the permitted time window.